Differential drive mechanism.



M. l. KELLY. DIFFERENTIAL DRWE MECHANISM.

PPLICATION FILED MAR. 30. 1914.

1,134,138. 2 SSSSSS SSSSS 1- yglTNESSES: M l ZyJEKNTZR.

am l-n 55 Wig, ATTORNEY.

ETF'RS CO.. FHOTC-LITHQ, WASHINGTON, D. (I.

MICHAEL J. KELLY, OF SOUTH LEE, MASSACHUSETTS.

DIFFERENTIAL DRIVE MECHANISM.

Specification of Letters Patent.

Patented Apr. 6,- 1915.

Application filed March 30, 1914.. Serial N 0. 828,130.

To all whom it may concern:

Be it known that I, MioHAnL J. KELLY, a citizen of the United States of America, residing in South Lee, in the county of Berkshire and State of Massachusetts, have invented certain new and useful Improvements in Differential Drive Mechanism, of which the following is a specification.

This invention relates to improvements in differential driving mechanism for automobiles and other self-propelled vehicles.

' object of the invention is to provide simple and efiicient mechanism for driving the rear axle of a motor vehicle, which, in addition to the usual driving functions, has differential functions as well.

Another object of the invention is to provide a novel form of ratchet mechanism in connection with divided axles which drives both axle sections either forwardly or backwardly at the same speed and allows one section to turn at a higher rate than the other when the vehicle is rounding a curve.

A further object is to improve generally and render more efficient the mechanical structure, as will be hereinafter more particularly pointed out.

In general my device consists of a driving gear or sprocket loosely mounted on the divided axles, two series of reversely arranged ratchet teeth in each face of the driving sprocket, pawl carrying disks mounted adj acent to the sprocket and keyed to each axle section, reversible pawls carried by these disks and adapted to engage either set of ratchet teeth to permit forward or backward movement of the driving gear and means to control the position of these pawls.

am aware that ratchet and pawl mechanism in differential driving devices is, in

general, disclosed to a considerable extent 111 the prior art. These devices, however, commonly employ ratchets with peripherally arranged teeth and pawls mounted on pivots outwardly extending from the driving gear. Consequently, with such devices, a severe strain is placed upon the pivot of the pawl which frequently results in the distortion or failure of the device at this point. I particularly avoid this trouble by arranging the ratchet teeth in the face of the sprocket or driving gear and by so mounting the pawls in the pawl carrying disk that the strain is transmitted directly to the disk itself and not upon the pivot on which the pawl is mounted.

One embodiment of my invention is illustrated in the accompanying drawings in which:

Figure l is a longitudinal section of my device on the center line thereof. Fig. 2 is a transverse sectional View taken on the line 2 2 of 1, looking in the direction of the arrows. I ig. 3 is a detail view of a portion of the driving sprocket. Fig. 4 is a sectional view on the line H of Fig. 3. Fig. 5 is a detail view illustrating the manner of mounting the pawls in the pawl carrying disk. Fig. 6 isa plan view of a portion of the pawl carrying disk.

Referring to the drawings, particularly to Figs. 1 and 2, l is the usual differential casing, made in two pieces bolted together and mounted centrally on the rear axle. The rear axle is of the divided type and comprises two sections 2, which are rotatably mounted in the casing l. Centrally located and loosely mounted on the axle sections 2 is the sprocket 3 which may be connected by means of a sprocket chain to any suitable form of motive power in the customary way. For convenience and purposes of illustration I show a sprocket wheel but I do not limit myself to this specific form of driving gear as other forms, for example, a bevel gear, may be substituted without departing from the scope of my invention.

On each face of the sprocket 3 are arranged two concentric rows of ratchet teeth land .5 (see Figs. 3 and 4). The teeth in row 4 are reversely arranged or oppositely disposed to those in the row 5, as clearly shown in Fig. 4E. Closely adjacent each face of the sprocket 3 are mounted the pawl carrying disks 6 which are keyed to the axle sections 2 and rotate therewith. It is to be noted particularly in this connection that the hubs of the disks are extended to meet the hubs on the difierential casing 1, thereby providing ample means to receive the end thrust to positively positioned on the shafts 2 by means of these same pawl bearing disks 6.

Mounted in each of the disks 6 are a number of pawls 7, four being shown in the drawings. Each pawl 7 (see Figs. 1, 2, 5 and 6) is disk; 6 f'which'iis amply proportioned; to receive such strain; 'lopermit 'the finishing;

in which the arms 25 and 26 respectively canu freely move. Furthermore, thevidiskffi, ,is provided with semi-cylindrical"finishedsur faces27 and 28.

25 of pawl 74 Similarly, the surface 28 receivesthe finished end of-arm"26"o1"r*'paw1 '71 Thus, as the end of each arm of pawl 7 abuts a finished surface, no strainis placed upon the spindle 9; Obviously any'strain refcei-lved in operation wouldbe transmitted directly-to and are'screwed to the dif sks'6;

Slidably -m'ounted onTfeather k'eys'in'the ""nected together-'and to aro'd' l6'b'y a pin '15 working 'in slotted holes in members Therrod' 16which passes through the casing l is an operating rod by means of which the awl' 7: maybe reversed 'asflwill-be described;

hubs of' disksj 6" are' disks .11." Thesedisk'sj aremaintained in the position shown in" Figl by the springs -17 and maybe forc'ed I" inwardly against springs 17"b'y means" of the "forked arms 18, theends 0t which-rest-"in circumferentialagrooves' 12 in members 11'-- These members '13 are pivotally mounted at crank extensions 18; The-latter are'con Pivotally mounted onthe disks 11'- are anumber of. links 10 which in turnflare' pivotally connected" to the lower'a'rms '26" of pawls', 7; This xconstruction'is clearly shown f these' figures that as'the links 10 "are "forced inwardly the arm 25 of'pawl7"will'be'with;

drawn from engagement with the ratchet teethintrow and the arm26willbe forced Thus'reverse' movement ispermitte'df The lows: With-the parts in the position shown", 7 in Figs; 1 and 2"Iand "assuming fthatth ec rod'16 may beconnected to the reverselever of the vehicleor may jbeiindependently operated inany suitable manner; V

The operation ofthe mechanismfisas rot;

sprocket .lS rotating "in" the direction of the .arrow' 31' '(seeFig. 2), it is obviousthat the ratchet teeth n rows L will drive disks 6 in. the direction of the arrow- 31 through" the arms 25'otpawls 7. Furthermore,feach section 2 of the rear' axle will be positively Now; assume that driven" at equal: speeds;

the vehicle'isroundinga curve, whichi'neces sitates 'di-fierential' rotation of the; axle sec tions, unless slipping" of the wheels is per 'mitted: The section 2'of the 'aXle'fiXed to r V the"wheelon*the inside. of the curve will be'positively driven, as before. Thepther} section "isyhowever, -permittedto' rotate fase' ter' by the construction shown. The disk"6 keyed to the latter section will "rotate "at to'permit'thi'sactionl 7 V Th8flb06-ll6blflllg wlththe advantages'in- V I possible with reverse movement-.=vo the sprocket 3. Whemthe-lat:

The surface-.21 isabovathev surface 28 and is adapted to receive the semi-M cylindricazlly; finished iendriof the upperrarma greaterspeed than the 3" the paw1s. 6 willsnap over he teeth inrow 4:;

cident thereto, are

ter is'reversed, the rod-16 is operated,' whih V -as previously described, removes the arms 25 from engagement with the teeth in rows.

l and forces the arms 26Yintd engagement 5' 5 1 with the teethfln rows 5? 1 Thus fthe axles2 are drivenil iai s fd ii t ni s It' "wnr; befse'en," hat-f1 havefprovrdedfat with" a novel"" arrangenient for? "'and '30 ratchet teeth"whichfinsurespositive' and-ire:

liable operation'ff Iti's' j tojbe undis'toodthat' I do "notflimit myself td the specific? struce tu're"disclosedf asxthe"scopefofmy inventrort; is more" truly" definedi'finf jthe "appended'fga *1. A"diflerentia1. "eehanismi ecirnprisingfj 7 V i sprocket or drivi'rigg'ge ar-looselytmoulitedbneo 14 in; the differential; casing 1 andhave bell" sitely disposed to theiteeth' 'in the'otherrow,

disks fixed to each axle secti'onand adjacent the 2' sprocket reversible" 1 pawls" mountedin' said disks and? normally in engagement and" means' to reverse"the 1 them to, engage the teeth"nfthe;other"row of=said,sprocket;" r

pawls'f to cause- 2; A" differential'j mechanism, jgcompri'singj 7 1n combination, dividedaxle "se'c'tl ns ratchet teethtinea'chff "'ce thereofifthe teetlil in "one" of "rows bein'g o ositely) dis 7: posed "to theiteeth"inithe other row, disk's'jln fiXed to each "axle section and fadj acent *the" V sprocket, reversible"pawlsimounted in said" disks and normaljly in"'en'ga'gernent with"the ratchet te'ethi'none of' saidjrowsiandmeans" to reverse thepawlsto cause them to engagey said means comprising jmembers ,sli'dably f mounted"andlrotatableiwith{said disks links I conn'ectir'ig "said members and said pa'wls,

springs to position saidflme'mbers'fro'm said 15 disks and "operativexmea'ns 1 to move "said.

" member's"aga nstjjsai'd springsito' reverse the pawls. V

' A differ ntial' mechanism comprising in 1 combinatiomf divided axle' sections, 'd'rivin'g' means loosely mounted onz'said sections; said means beinggprovided in each face thereof with'concentrlcally arranged rowsloffrat'cfhe't teeth," the teeth'm one "of "said rows; being; reversely arranged to the teeth in the other- 1,134,188 row, disks fixed to each axle section and engagement with the teeth in the other row, mounted adjacently to each face of the drivwhereby both axle sections are driven in 13 ing means, a plurality of double armed the same direction but in a reverse direction paWls mounted in each of said disks and to the former rotation. normally in engagement With the teeth in MICHAEL J. KELLY. one of said rows, whereby each axle section Witnesses: is driven in the same direction by said F. G. NEAL, sprocket, and means to force the pawls into E HARTWELL.

y addressing the "Commissioner of Patent: Washington, D. 0. 

